Sex- and age-dependent association of SLC11A1 polymorphisms with tuberculosis in Chinese: a case control study.

BACKGROUND: Host genetic factors are important determinants in tuberculosis (TB). The SLC11A1 (or NRAMP1) gene has been studied extensively for genetic association with TB, but with inconsistent findings. In addition, no study has yet looked into the effect of sex and age on the relationship between SLC11A1 polymorphisms and TB. METHODS: A case-control study was conducted. In total, 278 pulmonary TB patients and 282 sex- and age-matched controls without TB were recruited. All subjects were ethnic Chinese. On the basis of linkage disequilibrium pattern, three genetic markers from SLC11A1 and one from the nearby IL8RB locus were selected and examined for association with TB susceptibility. These markers were genotyped using single strand conformation polymorphism analysis or fragment analysis of amplified products. RESULTS: Statistically significant differences in allele (P = 0.0165, OR = 1.51) and genotype (P = 0.0163, OR = 1.59) frequencies of the linked markers SLC6a/b (classically called D543N and 3'UTR) of the SLC11A1 locus were found between patients and controls. With stratification by sex, positive associations were identified in the female group for both allele (P = 0.0049, OR = 2.54) and genotype (P = 0.0075, OR = 2.74) frequencies. With stratification by age, positive associations were demonstrated in the young age group (age < or =65 years) for both allele (P = 0.0047, OR = 2.52) and genotype (P = 0.0031, OR = 2.92) frequencies. All positive findings remained significant even after correction for multiple comparisons. No significant differences were noted in either the male group or the older age group. No significant differences were found for the other markers (one SLC11A1 marker and one IL8RB marker) either. CONCLUSION: This study confirmed the association between SLC11A1 and TB susceptibility and demonstrated for the first time that the association was restricted to females and the young age group.

Reliability, validity, and responsiveness of a 2-min walk test to assess exercise capacity of COPD patients.

PURPOSES: To investigate the reliability, validity, and responsiveness of a 2-min walk test (2MWT) in Chinese COPD patients with moderate-to-severe disease. METHODS: This study consisted of two parts. Forty-seven stable COPD patients with moderate-to-severe disease participated in the first part of study for the investigation of reliability and validity. The demographic and anthropomorphic data collected included age, gender, body weight, height, and body mass index. Each subject performed a pulmonary function test, a cardiopulmonary exercise test, three trials of a 2MWT, and two trials of 6-min-walk test (6MWT) in random order within a 5-day period. Fifteen of these subjects participated in the second part of study for the evaluation of the responsiveness of the 2MWT following pulmonary rehabilitation. The 2MWT and 6MWT were conducted before and after the program for comparison. RESULTS: Forty-five subjects (mean [+/- SD] age, 71.8 +/- 8.3 years; mean FEV1, 0.88 +/- 0.27 L) completed the first part of study, and 9 subjects (mean age, 74 +/- 8.7 years; mean FEV1, 0.94 +/- 0.28 L) completed the second part of study. The intraclass correlation coefficient of the repeated 2MWTs was high (R = 0.9994; p < 0.05), mean differences across trials ranged from 0.3 to 0.8 m (95% confidence interval, -3.1 to 4.6 m) demonstrated its high test-retest reliability. Significant correlations were found between the 2MWT and the 6MWT, the maximum oxygen uptake (V(O2)max) in milliliters per minute, and the V(O2)max in milliliters per kilogram per minute (r = 0.937, 0.454, and 0.555 respectively; p < 0.0125). Following rehabilitation, there were significant improvements in the mean 2MWT and 6MWT walking distance of 17.2 +/- 13.8 m and 60.6 +/- 35.5 m, respectively, with moderate effect sizes (0.61 and 0.53, respectively) and large standardized mean responses (1.25 and 1.70, respectively). High correlation was found between changes in the 2MWT and the 6MWT (r = 0.70; p < 0.05). CONCLUSION: The 2MWT was shown to be a reliable and valid test for the assessment of exercise capacity and responsive following rehabilitation in patients with moderate-to-severe COPD. It is practical, simple, and well-tolerated by patients with severe COPD symptoms.

Scanning laser polarimetry in pulmonary tuberculosis patients on chemotherapy.

INTRODUCTION: The aim of this study was to analyse the thickness of the retinal nerve fibre layer (RNFL) of pulmonary tuberculosis patients on ethambutol and isoniazid. MATERIALS AND METHODS: This was a prospective cohort study where patients with newly diagnosed pulmonary tuberculosis requiring chemotherapy, including ethambutol and isoniazid, were imaged using scanning laser polarimetry. Their mean baseline RNFL thickness and various scanning laser polarimetry parameters of both eyes were measured 2 weeks after the commencement of chemotherapy. The measurements were repeated at 3 months and 6 months after treatment. The various parameters of the baseline and the follow-up measurements were compared using paired sample t-test with Bonferroni correction. RESULTS: Twenty-four patients (16 males and 8 females; mean age, 51.0 +/- 17.6 years) were recruited. There was no statistically significant difference between the baseline and the follow-up measurements in RNFL thickness and all other scanning laser polarimetry parameters. CONCLUSION: In this cohort of subjects, there was no subclinical change in RNFL thickness detected by scanning laser polarimetry in pulmonary tuberculosis patients on chemotherapy, including ethambutol and isoniazid, after 6 months of treatment.